The present invention relates to an apparatus for applying a traffic stripe to a road. Specifically, the invention relates to improvements in the steering, versatility, line precision and material application in such an apparatus.
In applying a traffic stripe to a road, one normally uses either hot or cold traffic paint, cold tape or more durable materials such as epoxy or thermoplastic. The term road generally means routes, passes, or parking lots for motor vehicles, bikes or the like which are usually comprised of asphalt or portland concrete. Also, it is preferable, but not necessary, to add reflective material on top of the traffic stripe in order to make the traffic stripe reflective at night.
Traffic stripes generally come in two forms. There are long line stripes and transverse stripes. Long line stripes are typically lines dividing lanes of a road or a path. Normally one applies one interrupt white line or two solid yellow lines. An interrupted line is a series of predetermined length traffic stripes separated by a series of predetermined length gaps.
These interrupted lines and the solid lines are normally four inches wide. When two lines are applied, they are normally also separated by four inches. These dimensions do change, however, according to different country, state, county and city regulations.
In certain long line applications, one may also have a solid four inch line and an adjacent interrupted four inch line. These generally four inch lines are separated by a four inch spacing. They are normally used in situations were a plurality of center turn lanes (i.e., left hand turn lanes in the United States) are used in, for example, a three lane road.
Transverse lines are normally shorter markings or legends. Transverse lines are normally considered to be stop bars, crosswalks, railroad crossing markings, words such as "ONLY", arrows, symbols and other markings and legends of that nature. Since cars often come to stops on transverse markings, transverse lines are sometimes directly subject to the power applied to back wheels during acceleration of a motor vehicle. Thus, transverse lines generally undergo more wear than long line stripes. Consequently, transverse lines are normally thicker then long line stripes.
Generally, when thermoplastic is used, stripes are usually applied in thicknesses of sixty to a hundred and twenty-five thousandths of an inch. Specifically, they are usually applied at ninety to one hundred and twenty-five thousandths of an inch.
An example of a traffic stripe applicator is the Mini Mac 150 by Marcato Enterprises, Inc. The Mini Mac 150 is generally considered to be what is known as a handliner, mainly because it is manually propelled. The Mini Mac 150 includes an oil heated holding tank and thermoplastic pump as well as a thermoplastic application housing to perform adjustable line widths from four inches to twelve inches. Since, however, the thermoplastic application housing lies co-linear with the axle on the front wheels, a transverse line such as a crosswalk cannot apparently extend closer then sixteen inches to a curb. In addition, despite locking the lone rear wheel, the Mini Mac 150 has difficulty in laying down long straight lines. Long line application with the Mini Mac 150 is also difficult, because the Mini Mac has a limited capacity of only one hundred fifty pounds of thermoplastic material. Also, although two solid lines can be applied by the one thermoplastic assembly of the Mini Mac 150, one would have to make two separate trips to lay down a solid line with an adjacent interrupted line.
The Mini Mac 1000 by Marcato Enterprises, Inc. includes four wheel steering for long line operation. The Mini Mac 1000 also includes a thermoplastic applicator which is attached to the frame. Since the applicator is mounted on the vehicle frame, the applicator does not turn at the same angle as the adjacent front wheel. Thus, in curved line applications, when for example, a twelve inch line is being applied, the line width will likely narrow to about seven inches as the radius of the curve about which the applicator travels gets smaller. Thus, instead of a twelve inch width curved stripe, one would end up with an undesirable narrowing curve.
U.S. Pat. No. 3,477,352 to Harding et al. discloses a system for controlling the operation of its spray gun so that interrupted lines can be applied. Harding, however, fails to address many problems for both long lines and for transverse markings which the present invention overcomes.
It is desirable to have an apparatus perform both high production straight and curved lines. This capability is important especially in medium size jobs where, for example, there has been a resurfacing of an intersection. In such a situation, one must have the capability to apply relatively high-speed long lines and to apply a plurality of transverse markings in a relatively fast time. In these medium size applications, one can not usually justify the high cost associated with a large long line striping truck to apply, for example, approximately 2,000 feet of long lines. However, if one tried to use handliners in such an application, it would likely be relatively slow, relatively imprecise and costly in labor.
In summary, there is a need for an apparatus which can perform precision long lines in a more cost-efficient manner and there is also a need for an apparatus which can perform accurate transverse markings in a more cost-efficient manner.